Developer k6lcm has released NES Radar, a homebrew Nintendo Entertainment System cartridge that displays live flight traffic on the TV screen. Typing in an ICAO airport code such as KATL pulls up nearby aircraft as blips, despite the name, no radar hardware or radio receiver sits inside the cartridge. The project is a plain ROM cart plus a custom cable, published under the GPL on GitHub.

The trick is in that cable. It plugs into the NES's second controller port, repurposed as an improvised serial connection. A Python script running on a separate computer fetches current aircraft positions and streams the data to the console over that link, no ESP32 or Pi Pico hidden inside the cart.

Because the software can only render 8 sprites for this purpose, busy hubs will not show every plane in the sky. KATL, Atlanta's Hartsfield-Jackson, happens to be the world's busiest airport, so its full traffic never fits on screen at once.

NES Radar builds on k6lcm's earlier c64u-radar, which uses the same Python-server setup but reads aircraft data through a Commodore 64 Ultimate's built-in LAN port instead. The NES has no such port, so the controller connector became the data channel by necessity. Hackaday points out that a comparable controller-port serial hack was used for satellite tracking on the NES back in 2020.